Is there a possibility to allow for the under-ride / Mansfield bars to become a removable part on the trailers? It's odd that so many things can be altered (even the mudflaps) but the bar is permanent. It would allow for some gruesome collisions if we could delete it.
I think that I did this once and posted it on forums. There was a person who needed it to be removed for some crash testing, it was some time ago though so finding might be an issue and I'm not sure if it still works.